The present disclosure relates to storage media and information processing devices for exchanging data with a secondary storage section through cache.
A generic information processing device uses a cache system to improve processing speed in a situation in which data is exchanged with an auxiliary storage device that has relatively slow processing speed.
For example, when a reading request from an application program or an operating system (OS) is generated with respect to data stored in a magnetic disk device, in addition to the data read from the magnetic disk device being passed onto a process that has requested reading of the data, the read data is also stored in a semiconductor disk device that forms a disk cache.
When another request for reading data stored in the magnetic disk device is subsequently generated, in a situation in which the requested data is also stored in the semiconductor disk device, the requested data is read from the semiconductor disk device. As a result, a central arithmetic processor can read the data at high-speed.
The semiconductor disk device is formed by flash memory. Therefore, data (cache data) stored in the semiconductor disk device is not deleted and remains stored even if the power supply to the system is cut off and the system is subsequently restarted. Therefore, when the power supply to the system is cut off, high hit ratio contents of the disk cache that have been structured up until the time that the power supply is cut off can be effectively maintained.
With respect to program code for an executed program and data that is required for processing, an OS typically reads the program code and the data into a primary storage section from a secondary storage section when reading thereof is required. The OS also performs caching of the program code and the data when performing the reading thereof.